Process for producing optically active 1,3-butanediol by asymmetric assimilation

ABSTRACT

An optically active 1,3-butanediol can be produced by either (1) treating a mixture of 1,3-butanediol enantiomers with a microorganism, which has been optionally treated, capable of asymmetrically assimilating said mixture, or (2) preparing a microorganism, which has been optionally treated, capable of asymmetrically reducing 4-hydroxy-2-butanone, and collecting optically active 1,3-butanediol.

This application is a divisional of application Ser. No. 07/449,929 ,filed on Dec. 7, 1989, now U.S. Pat. No. 5,219,757, the entire contentsof which are hereby incorporated by reference.

FIELD OF INDUSTRIAL APPLICATION

The present invention relates to a process for producing opticallyactive 1,3-butanediol with a microorganism.

Optically active 1,3-butanediol is an important starting material forvarious medicines such as antibiotics.

PRIOR ART

Known processes for producing optically active 1,3-butanediol include(1) a process wherein a chemically synthesized mixture of 1,3-butanediolracemates is optically resolved with an optical resolving agent (cf.Japanese Patent Laid-Open No. 191631/1986) and (2) a process wherein itis produced from 4-hydroxy-2-butanone by asymmetric synthesis with aRaney nickel catalyst treated with an optically active compound [cf.Japanese Patent Laid-Open No. 204187/1983 and Bull. Chem. Soc. Jpn., 53,1356 to 1360 (1980)]. However, both the processes (1) and (2) have adefect that expensive optical resolving agent and catalyst must be usedand, in addition, the product obtained by the process (2) has a lowoptical purity. Under these circumstances, it is demanded to establish aprocess for producing optically active 1,3-butanediol having a highoptical purity in an economically advantageous and convenient manner.

DISCLOSURE OF THE INVENTION

The present invention provides a process for producing optically active1,3-butanediol which comprises either (1) treating a mixture of1,3-butanediol enantiomers with a microorganism, which has beenoptionally treated, capable of asymmetrically assimilating said mixture,or (2) preparing a microorganism, which has been optionally treated,capable of asymmetrically reducing 4-hydroxy-2-butanone, and collectingoptically active 1,3-butanediol.

The present invention involves (1) asymmetric assimilation and (2)reduction as follows:. (1) a process for producing optically active1,3-butanediol which comprises treating a mixture of 1,3-butanediolenantiomers with a microorganism, which has been optionally treated,capable of asymmetrically assimilating said mixture and collectingoptically active 1,3-butanediol remaining intact, and (2) a process forproducing optically active 1,3-butanediol which comprises treating4-hydroxy-2-butanone with a microorganism, which has been optionallytreated, capable of asymmetrically reducing 4-hydroxy-2-butane intoeither (R)-1,3-butanediol or (S)-1,3-butanediol and collecting the(R)-1,3-butanediol or (S)-1,3-butanediol thus formed.

The present invention will now be described in detail by referring tothese two processes.

(1) Asymmetric Assimilation

After intensive investigations made for the purpose of getting amicroorganism usable for producing optically active 1,3-butanediolhaving a high optical purity by asymmetric assimilation, the inventorshave found that a microorganism selected from among those belonging tothe genera Brevibacterium, Candida, Enterobacter, Geotrichum,Klebsiella, Lodderomyces, Pseudomonas, Rhodotorula, Saccharomyces,Saccharomycopsis, Sterigmatomyces and Trichosporon is capable ofasymmetrically assimilating a mixture of 1,3-butanediol enantiomers toleave (R)-1,3-butanediol intact, and that a microorganism selected fromamong those belonging to the genera Agrobacterium, Azotobacter,Bacillus, Brettanomyces, Candida, Citrobacter, Corynebacterium, Dekkera,Endomyces, Erwinia, Hansenula, Issatchenkia, Klebsiella, Kluyveromyces,Geotrichum, Micrococcus, Mycobacterium, Pachysolen, Paracoccus, Pichia,Protaminobacter, Pseudomonas, Saccharomyces, Saccharomycopsis,Selenotila, Serratia, Stephanoascus and Xanthomonas is capable ofasymmetrically assimilating a mixture of 1,3-butanediol enantiomers toleave (S)-1,3-butanediol intact.

The microorganism usable in the present invention may be any of thosebelonging to the genus Brevibacterium, Candida, Enterobacter,Geotrichum, Klebsiella, Lodderomyces, Pseudomonas, Rhodotorula,Saccharomyces, Saccharomycopsis, Sterigmatomyces or Trichosporon capableof asymmetrically assimilating a mixture of 1,3-butanediol enantiomersto leave (R)-1,3-butanediol intact or any of those belonging to thegenus Agrobacterium, Azotobacter, Bacillus, Brettanomyces, Candida,Citrobacter, Corynebacterium, Dekkera, Endomyces, Erwinia, Hansenula,Issatchenkia, Klebsiella, Kluyveromyces, Geotrichum, Micrococcus,Mycobacterium, Pachysolen, Paracoccus, Pichia, Protaminobacter,Pseudomonas, Saccharomyces, Saccharomycopsis, Selenotila, Serratia,Stephanoascus or Xanthomonas capable of asymmetrically assimilating amixture of 1,3-butanediol enantiomers to leave (S)-1,3-butanediolintact.

The microorganisms capable of asymmetrically assimilating a mixture of1,3-butanediol enantiomers to leave (R)-1,3-butanediol intact includeBrevibacterium iodinum IFO 3558, Candida rugosa IFO 1364, Candidaparapsilosis IFO 0640, Candida parapsilosis IFO 0708, Candidaparapsilosis IFO 1396, Enterobacter cloacac ATCC 7256, Geotrichumcandidum IFO 4601, Geotrichum candidum IFO 5767, Geotrichum candidum IFO5368, Geotrichum rectangulatum JCM 1750, Geotrichum klebahnii JCM 2171,Geotrichum fermentans JCM 2467, Geotrichum capitatum JCM 3908,Geotrichum eriense JCM 3912, Klebsiella pneumoniae IFO 12019,Lodderomyces elongisporus IFO 1676, Psudomonas diminuta IFO 12697,Rhodotorula glutinis IFO 0395, Saccharomyces cerevisiae AHU 3402,Saccharomycopsis lipolytica ITO 1550, Sterigmatomyces elviae DSM 70852,Trichosporon cutaneum IFO 1198 and Trichosporon capitatum IFO 0743.

The microorganisms capable of asymmetrically assimilating a mixture of1,3-butanediol enantiomers to leave (S)-1,3-butanediol intact includeAgrobacterium radiobacter IFO 12664, Azotobacter chroococcum IFO 12994,Bacillus brevis IFO 3331, Bacillus cereus AHU 1707, Bacillus cereus AHU1355, Bacillus sphaericus IFO 3525, Bacillus sphaericus IFO 3341,Bacillus subtilis IFO 3007, Bacillus subtilis IFO 3037, Brettanomycesabstines DSM 70726, Candida cariosilignicola DSM 2148, Candida kefyr(Beijerinck) DSM 70073, Candida krusei (Castellani) DSM 70025, Candidasucciphila DSM 2149, Candida utilis IFO 0639, Candida utilis IFO 0626,Citrobacter freundii AHU 1534, Corynebacterium glutamicum ATCC 13032,Corynebacterium michiganense IFO 13762, Dekkera bruxellensis IFO 1590,Endomyces decipien IFO 0102, Erwinia carotovora subsp. carotovora IFO3830, Geotrichum fragrans JCM 1749, Hansenula anomala DSM 70130,Hansenula minuta DSM 70274, Hansenula subpelliculosa IFO 0808, Hansenulawickerhamii DSM 70280, Hansenula wingel DSM 10281, Issatchenkiascutulata var. scutulata IFO 10070, Klebsiella pneumoniae IFO 12059,Kluyveromyces drosophilarum IFO 1012, Kluyveromyces lactis IFO 1267,Kluyveromyces lactis IFO 1903, Micrococcus luteus IFO 3333, Micrococcusroseus IFO 3764, Mycobacterium smegmatis IFO 3153, Pachysolentannophilus IFO 1007, Paracoccus denitrificans IFO 12442, Pichiacellobiosa DSM 2147, Pichia farinosa IFO 1163, Pichia heedii IFO 10020,Pichia heedii IFO 10019, Pichia lindnerii DSM 70718, Pichia opuntiaevar. thermotolerans IFO 10026, Pichia opuntiae var. thermotolerans IFO10025, Pichia pastoris DSM 70382, Pichia querquum DSM 70386, Pichiasargentensis DSM 70388, Pichia trehalophia DSM 70391, Protaminobacterruber IAM 1081, Pseudomonas acidovorans IFO 13582, Pseudomonas diminutaIFO 12697, Pseudomonas fluorescens IFO 12055, Pseudomonas fluorescensIFO 3081, Pseudomonas putida IFO 3738, Saccharomyces cerevisiae IAM0216, Saccharomycopsis fibuligera IFO 0103, Selenotila peltata DSM70579, Serratia marcescens IAM 1105, Stephanoascus ciferrii IFO 1854,Xanthomonas maltophilia IFO 12690 and Xanthomonas oryzae IAM 1657.

Each strain may be either a wild type, a variant or a recombinantobtained by genetic engineering such as cell fusion or generecombination.

Microorganisms having IFO numbers assigned thereto are described in theList of Cultures, 8th ed., vol. 1 (1988) published by the Institute forFermentation, Osaka (IFO) and available therefrom. Those having AHUnumbers are described in the Catalogue of Cultures, 4th ed. (1987)published by Japan Federation of Culture Collection (JFCC) and availablefrom the Faculty of Agriculture, Hokkaido University. Those having ATCCnumbers are described in the Catalogue of Bacteria Phages rDNA Vectors,16th ed. (1985) published by American Type Culture Collection (ATCC) andavailable therefrom. Those having JMC numbers are described in theCatalogue of Strains, 3rd ed. (1986) published by Japan Cellection ofMicroorganisms, RIKEN and available therefrom. Those having IAM numbersare available from the Institute of Applied Microbiology, the Universityof Tokyo. Those having DSM numbers are described in the Catalog ofStrains (1983) published by Deutsche Sammlung von Mikroorganismen (DSM)and available therefrom.

The following strains were deposited at the Institute for Fermentation,Osaka, 17-85 Juso-honmachi 2-chome, Yodogawa-ku, Osaka Japan asindicated:

    ______________________________________                                        Strain         Accession Number                                                                            Deposit Date                                     ______________________________________                                        Kluveromyces lactis                                                                          IFO 1267      Dec. 9, 1964                                     Pichia opuntiae                                                                              IFO 10025     Mar. 19, 1982                                    Geotricum candidum                                                                           IFO 5368      1952                                             Candida utilis IFO 0639      1954                                             Candida parapsilosis                                                                         IFO 1396      June 1, 1967                                     Brevibacterium iodinium                                                                      IFO 3558      May 30, 1957                                     Xanthomonas maltophilia                                                                      IFO 12690     July 31, 1968                                    Stephanoascus ciferrii                                                                       IFO 1854      Aug. 23, 1977                                    Paracoccus denitrificans                                                                     IFO 12442     Sept. 15, 1966                                   Pachysolen tannophilus                                                                       IFO 1007      Aug. 24, 1954                                    Mycobacterium smegmatis                                                                      IFO 3153      Sept. 17, 1952                                   Micrococcus luteus                                                                           IFO 3333      Aug. 24, 1954                                    Klebsiella pneumoniae                                                                        IFO 12059     Sept. 9, 1964                                    Issatchenkia scutulata                                                                       IFO 10070     Jan. 14, 1983                                    var. scutulata                                                                Hansenula subpelliculosa                                                                     IFO 0808      Nov. 13, 1956                                    Erwinia cartovora                                                                            IFO 3830      Oct. 12, 1959                                    subsp. cartovora                                                              Endomyces decipiens                                                                          IFO 0102      1946                                             Dekkera bruxellensis                                                                         IFO 1590      May 6, 1971                                      Corynebacterium                                                                              IFO 13762     Sept. 19, 1977                                   michiganese                                                                   Bacillus subtilis                                                                            IFO 3007      1946                                             Azotobacter chroococcum                                                                      IFO 12994     July 1, 1969                                     Agrobacterium  IFO 12664     July 31, 1968                                    radiobacter                                                                   Trichosporon cutaneum                                                                        IFO 1198      Sept. 6, 1963                                    Saccharomycopsis                                                                             IFO 1550      May 27, 1970                                     lipolytica                                                                    Rhodotorula glutinis                                                                         IFO 0395      1941                                             Pseudomonas diminuta                                                                         IFO 12697     July 31, 1968                                    Lodderomyces   IFO 1676      Dec. 17, 1975                                    elongisporus                                                                  Klebsiella pneumoniae                                                                        IFO 12009     May 25, 1963                                     Pseudomonas putida                                                                           IFO 3738      June 21, 1958;                                   ______________________________________                                    

In addition, a culture of Serratia marcescens, assigned the accessionnumber IAM 1105, was deposited at the Institute of Applied Microbiology,at the University of Tokyo, Japan, prior to Dec. 25, 1992.

The above deposits were made as to afford a permanently viable stock of,and ready public accessibility to, the indicated strains so as to allowpractice of the invention described in this patent document. Samples ofeach of these strains will be made available to the public (1) for theterm of 30 years, (2) for five years after the last request for a sampleof a deposited strain or (3) for the enforceable life of any patentwhich issues from this document, whichever is longer.

The culture medium used in the present invention is not particularlylimited so far as the microorganism can grow in or on it. The carbonsource may be any of carbon nutrients for growing the microorganism. Thecarbon sources include, for example, saccharides such as glucose,fructose, sucrose and dextrin; alcohols such as sorbitol, ethanol andglycerol; organic acids such as fumaric, citric, acetic and propionicacids and salts thereof; hydrocarbons such as paraffin; and mixtures ofthem. The nitorgen sources include inorganic and organic nitrogenouscompounds such as ammonium salts of inorganic acids, e.g., ammoniumchloride, ammonium sulfate and ammonium phosphate; ammonium salts oforganic acids, e.g., ammonium fumarate and ammonium citrate; meatextract; yeast extract; corn steep liquor; casein hydrolyzate; urea aswell as mixtures thereof. Furthermore various nutritional sourcescommonly used in the culture of microorganisms, such as inorganic salts,trace metal salts and vitamins, may be appropriately mixed and used inthe present invention. In addition, materials effective in promoting thegrowth of the microorganism, in elevating the productivity of the targetcompound of the present invention or in maintaining the pH value of themedium on the desired level may be added, if required.

The pH value of the medium may be adjusted to 3.0 to 9.5, preferably 4to 8. The culture may be carried out at a temperature of 20° to 45° C.,preferably 25° to 37° C., either aerobically or anaerobically underconditions suitable for the growth of the microorganism for 5 to 120hours, preferably about 12 to 72 hours.

The asymmetric assimilation may be effected by using the culture mediumas such. Alternately, the cells may be separated by, for example,centrifugation, optionally washed and resuspended in a buffer solutionor water. Then the mixture of 1,3-butanediol enantiomers may be added tothe suspension thus obtained. In this reaction, it is sometimespreferable to add a carbon source such as glucose or sucrose to themedium to thereby supply energy. The cells may be used as such in theform of viable cells. Alternately, they may be ground, treated withacetone or lyophilized. These cells, which have been optionally treated,may be immobilized prior to the use by a conventional method such as thepolyacrylamide gel, sulfur-containing polysaccharide gel (such ascarrageenan gel), alginic acid gel or agar gel method. Furthermore, anenzyme obtained from said treated cells by combining known methods maybe used in the present invention.

The mixture of 1,3-butanediol enantiomers may be added either at once atthe initiation of the reaction or in portions in the course of thereaction either as such, dissolved in water or an inert organic solventor dispersed in, for example, a surfactant.

The reaction may be conducted at a pH value of 3 to 10, preferably 5 to9, at 10° to 60° C., preferably 20° to 40° C. for 1 to 120 hours with orwithout stirring. A prolonged reaction time causes a reduction in theamount of the remaining 1,3-butanediol, though an optically active1,3-butanediol having a high optical purity can be obtained in thiscase. The concentration of the substrate may range preferably from about0.1 to 10%, though it is not restricted thereto.

The optically active 1,3-butanediol remaining intact after the reactioncan be easily collected by extracting the reaction mixture, from whichthe cells have been optionally separated, with an organic solvent andpurifying the extract by, for example, distillation or columnchromatography.

(2) Reduction

After intensive investigations made for the purpose of getting amicroorganism usable for producing optically active 1,3-butanediolhaving a high optical purity by asymmetric reduction, the inventors havefound that a microorganism selected from among those belonging to thegenera Ambrosiozyma, Bacillus, Candida, Citrobacter, Corynebacterium,Hansenula, Issatchenkia, Kluyveromyces, Pichia, Protaminobacter,Pseudomonas, Rhodotorula, Selenotila, Schizosaccharomyces, Stephanoascusand Xanthomonas is capable of asymmetrically reducing4-hydroxy-2-butanone into (R)-1,3-butanediol, and that a microorganismselected from among those belonging to the genera Brevibacterium,Candida, Geotrichum, Klebsiella, Lodderomyces, Saccharomycopsis andTrichosporon is capable of asymmetrically reducing 4-hydroxy-2-butanoneinto (S)-1,3-butanediol.

The microorganism usable in the present invention may be any of thosebelonging to the genus Ambrosiozyma, Bacillus, Candida, Citrobacter,Corynebacterium, Hansenula, Issatchenkia, Kluyveromyces, Pichia,Protaminobacter, Pseudomonas, Rhodotorula, Selenotila,Schizosaccharomyces, Stephanoascus or Xanthomonas capable ofasymmetrically reducing 4-hydroxy-2-butanone into (R)-1,3-butanediol orany of those belonging to the genus Brevibacterium, Candida, Geotrichum,Klebsiella, Saccharomycopsis or Trichosporon capable of asymmetricallyreducing 4-hydroxy-2-butanone into (S)-1,3-butanediol.

The microorganisms capable of forming (R)-1,3-butanediol from4-hydroxy-2-butanone include Ambrosiozyma cicatricosa IFO 1846, Bacillussereus AHU 1355, Bacillus subtilis IFO 3007, Candida cariosilignicolaDSM 2148, Candida arborea IAM 4147, Candida kefyr (Beijerinck) DSM70073, Candida krusei (Castellani) DSM 70075, Candida guilliermondii IAM4412, Candida succiphila DSM 2149, Candida utilis IFO 0639, Candidautilis IFO 0626, Candida utilis IAM 4277, Citrobacter freundii AHU 1534,Corynebacterium michiganense IFO 13762, Hansenula polymorpha ATCC 26012,Hansenula minuta DSM 70274, Hansenula subpelliculosa IFO 0808, Hansenulafabianii IFO 1254, Hansenula wickerhamii DSM 70280, Hansenula wingei DSM10281, Issatchenkia scutulata var. scutulata IFO 10070, Issatchenkiascutulata var. scutulata IFO 10069, Kluyveromyces drosophilarum IFO1012, Kluyveromyces lactis IFO 1267, Kluyveromyces lactis IFO 1903,Pichia cellobiosa DSM 2147, Pichia heedii IFO 10019, Pichia heedii IFO10020, Pichia lindnerii DSM 70718, Pichia opuntiae var. thermotoleransIFO 10025, Pichia pastoris DSM 70382, Pichia trehalophia DSM 70391,Protaminobacter ruber IAM 1081, Pseudomonas diminuta IFO 12697,Pseudomonas fluorescens IFO 3081, Pseudomonas putida IFO 3738,Rhodotorula rubra IFO 0383, Selenotila peltata DSM 70579,Schizosaccharomyces pombe IFO 0363, Stephanoascus ciferrii IFO 1854 andXanthomona maltophilia IFO 12690. The microorganisms capable of forming(S)-1,3-butanediol from 4-hydroxy-2-butanone include Brevibacteriumiodinum IFO 3558, Candida rugosa IFO 1664, Candida parapsilosis IFO0640, Candida parapsilosis IFO 0708, Candida parapsilosis IFO 1396,Geotrichum candidum IFO 4601, Geotrichum candidum IFO 5767, Geotrichumcandidum IFO 5368, Geotrichum rectangulatum JCM 1750, Geotrichumklebanoii JCM 2171, Geotrichum fermentans JCM 2467, Geotrichum capitatumJCM 3908, Geotrichum eriense JCM 3912, Klebsiella pneumoniae IFO 12019,Lodderomyces elongisporus IFO 1676, Saccharomycopsis lipolytica ITO1550, Trichosporon cutaneum IFO 1198 and Trichosporon capitatum IFO0743.

Each strain may be either a wild type, a variant or a recombinantobtained by genetic engineering such as cell fusion or generecombination.

Microorganisms having IFO numbers assigned thereto are described in theList of Cultures, 8th ed., vol. 1 (1988) published by the Institute forFermentation, Osaka (IFO) and available therefrom. Those having AHUnumbers are described in the Catalogue of Cultures, 4th ed. (1987)published by Japan Federation of Culture Collection (JFCC) and availablefrom the Faculty of Agriculture, Hokkaido University. Those having JCMnumbers are described in the Catalogue of Strains, 3rd ed. (1986)published by Japan Collection of Microorganisms, RIKEN and availabletherefrom. Those having ATCC numbers are described in the Catalogue ofBacteria Phages rDNA Vectors, 16th ed. (1985) and the Catalogue ofFungi/Yeast, 17th ed. (1987) published by American Type CultureCollection (ATCC) and available therefrom. Those having DSM numbers aredescribed in the Catalog of Strains (1983) published by DeutscheSammlung von Mikroorganismen (DSM) and available therefrom. Those havingIAM numbers are available from the Institute of Applied Microbiology,the University of Tokyo.

The culture medium used in the present invention is not particularlylimited so far as the microorganism can grow in or on it. The carbonsource may be any of carbon nutrients for growing the microorganism. Thecarbon sources include, for example, saccharides such as glucose,fructose, sucrose and dextrin; alcohols such as sorbitol, ethanol andglycerol; organic acids such as fumaric, citric, acetic and propionicacids and salts thereof; hydrocarbons such as paraffin; and mixtures ofthem. The nitrogen sources include inorganic and organic nitrogenouscompounds such as ammonium salts of inorganic acids, e.g. ammoniumchloride, ammonium sulfate and ammonium phosphate; ammonium salts oforganic acids, e.g. ammonium fumarate and ammonium citrate; meatextract; yeast extract; corn steep liquor; casein hydrolyzate; urea aswell as mixtures thereof. Furthermore various nutritional sourcescommonly used in the culture of microorganisms, such as inorganic salts,trace metal salts and vitamins, may be appropriately mixed and used inthe present invention. In addition, materials effective in promoting thegrowth of the microorganism, in elevating the productivity of the targetcompound of the present invention or in maintaining the pH value of themedium on the desired level may be added, if required.

The pH value of the medium may be adjusted to 3.0 to 9.5, preferably 4to 8. The culture may be carried out at a temperature of 20° to 45° C.,preferably 25° to 37° C., either aerobically or anaerobically underconditions suitable for the growth of the microorganism for 5 to 120hours, preferably about 12 to 72 hours.

The reduction may be effected by using the culture medium as such.Alternately, the cells may be separated by, for example, centrifugation,optionally washed and resuspended in a buffer solution or water. Then4-hydroxy-2-butanone may be added to the suspension thus obtained. Inthis reaction, it is sometimes preferable to add a carbon source such asglucose or sucrose to the medium to thereby supply energy. The cells maybe used as such in the form of viable cells. Alternately, they may beground, treated with acetone or lyophilized. These cells, which havebeen optionally treated, may be immobilized prior to the use by aconventional method such as the polyacrylamide gel, sulfur-containingpolysaccharide gel (such as carrageenan gel), alginic acid gel or agargel method. Furthermore, an enzyme obtained from said treated cells bycombining known methods may be used in the present invention.

The 4-hydroxy-2-butanone may be added either at once at the initiationof the reaction or in portions in the course of the reaction either assuch, dissolved in water or an inert organic solvent or dispersed in,for example, a surfactant.

The reaction may be conducted at a pH value of 3 to 9, preferably 5 to8, at 10° to 60° C., preferably 20° to 40° C. for 1 to 120 hours with orwithout stirring. The concentration of the substrate may preferablyrange from about 0.1 to 10%, though it is not restricted thereby.

The optically active 1,3-butanediol thus formed may be readily collectedby extracting the reaction mixture, from which the cells may beoptionally separated, with an organic solvent and purifying the extractby, for example, distillation or column chromatography.

EXAMPLES

The following Examples will further illustrate the present invention,which by no means limit the present invention.

In the following Examples, 1,3-butanediol in the reaction liquid mixturewas easily determined according to gas chromatography [column: Thermon3000, (2m), 130° C.] and the optical purity was determined byacetylating optically active 1,3-butanediol obtained by the reactionwith acetyl chloride by an ordinary method and subjecting it to highperformance liquid chromatography with an optical resolution column[column: Chiral cel OB (mfd. by Daicel Chemical Industries, Ltd.),solvent: n-hexane/2-propanol=19:1, wavelength: 220 nm, flow rate: 0.5ml/min) [retention time: 15 min for (S)-enantiomer and 19.3 min for(R)-enantiomer].

Example 1

    ______________________________________                                        <Microorganism-producing culture medium>                                      ______________________________________                                               glucose  1.0%                                                                 yeast extract                                                                          0.3%                                                                 peptone  0.5%                                                                 1,3-butanediol                                                                         0.5%                                                                 K.sub.2 HPO.sub.4                                                                      0.1%                                                                 MgSO.sub.4.7H.sub.2 O                                                                   0.05%                                                                        pH 7.2                                                        ______________________________________                                    

100 ml of the microorganism-producing culture medium having theabove-described composition was put in a 500-ml Sakaguchi flask. Aftersterilization followed by inoculation with a microorganism shown inTable 1, the shaking culture was conducted at 30° C. for 48 h. Then themicroorganism was separated by centrifugation and washed withphysiological saline once to give viable cells.

Then 50 ml of distilled water was put in a 500-ml Sakaguchi flask, inwhich the microorganism obtained as described above was suspended. 0.5 gof racemic 1,3-butanediol was added to the suspension and the reactionwas conducted under reciprocal shaking at 30° C. for 48 h.

After the completion of the reaction followed by removal of the cells bycentrifugation, the supernatant liquid was saturated with sodiumchloride and extracted with 50 ml of ethyl acetate. The ethyl acetatelayer was analyzed according to gas chromatography to determine theamount of remaining 1,3-butanediol.

Thereafter ethyl acetate was dehydrated with anhydrous Glauber's salt.After removing the solvent, a syrup was obtained. The syrup wasacetylated with acetyl chloride by an ordinary method and the productwas dissolved in a solvent and analyzed according to high performanceliquid chromatography to determine the absolute configuration and theoptical purity of obtained 1,3-butanediol.

The results are shown in Table 1.

Example 2

Candida parapsilosis IFO 1396 was put in a 10-l jar fermenter containing5 l of the same culture medium as that used in Example 1 and culturedunder stirring at 250 r.p.m. at 30° C. for 24 h. The flow rate was 0.5v.v.m. After the completion of the culture, the cells were collected byfiltration, washed with 5 l of water and suspended in 500 ml of water.10 g of racemic 1,3-butanediol was added to the suspension and themixture was stirred at 30° C. for 48 h to conduct the reaction. Afterthe completion of the reaction, the cells were removed bycentrifugation. The obtained supernatant liquid was saturated withsodium chloride and extracted with 250 ml of ethyl acetate twice. Theethyl acetate layer was dehydrated with anhydrous Glauber's salt. Afterremoving the solvent under reduced pressure, 4.2 g of a syrup wasobtained. The syrup was distilled under reduced pressure to give 4.0 gof colorless transparent (R)-1,3-butanediol. The product had a specificrotatory power [α]_(D) ²⁰ of -28° (C=1 in EtOH), an absoluteconfiguration of the (R)-enantiomer and an optical purity determined byHPLC analysis of 96% e.e.

Example 3

Geotrichum candidum IFO 4601 was cultured and the reaction andextraction were conducted in the same manner as that of Example 2 togive 4.0 g of a syrup. 1,3-Butanediol thus obtained was analyzed toreveal that it had an absolute configuration of the (R)-enantiomer andan optical purity of 90% e.e.

Example 4

Candida utilis IFO 0639 was cultured and the reaction and extractionwere conducted in the same manner as that of Example 2 to give 4.9 g ofa syrup. 1,3-Butanediol thus obtained was analyzed to reveal that it hadan absolute configuration of the (S)-enantiomer and an optical purity of92% e.e.

Example 5

Pichia opuntiae var. thermotolerans IFO 10025 was cultured and thereaction and extraction were conducted in the same manner as that ofExample 2 to give 3.7 g of a syrup. 1,3-Butanediol thus obtained wasanalyzed to reveal that it had an absolute configuration of the(S)-enantiomer and an optical purity of 97% e.e.

                                      TABLE 1                                     __________________________________________________________________________                     Amount of      Optical                                                        remaining      purity of                                                      1,3-butanediol                                                                       Absolute                                                                              1,3-butanediol                                Microorganism    (mg/ml)                                                                              configuration                                                                         (% e.e.)                                      __________________________________________________________________________    Brevibacterium iodinum IFO 3558                                                                2.4    R       51                                            Candida rugosa IFO 1364                                                                        6.4    R       36                                            Candida parapsilosis IFO 0640                                                                  5.8    R       50                                            Candida parapsilosis IFO 0708                                                                  5.3    R       55                                            Candida parapsilosis IFO 1396                                                                  4.0    R       98                                            Enterobacter cloacae ATCC 7256                                                                 6.4    R       32                                            Geotrichum candidum IFO 4601                                                                   1.9    R       94                                            Geotrichum candidum IFO 5767                                                                   2.4    R       80                                            Geotrichum candidum IFO 5368                                                                   2.6    R       98                                            Geotrichum retangulatum JCM 1750                                                               4.0    R       74                                            Geotrichum klebahnii JCM 2171                                                                  5.0    R       58                                            Geotrichum fermentans JCM 2467                                                                 4.0    R       88                                            Geotrichum capitatum JCM 3908                                                                  5.5    R       40                                            Geotrichum eriense JCM 3912                                                                    6.1    R       23                                            Klebsiella pneumonias IFO 1209                                                                 5.5    R       30                                            Lodderomyces elongisporus                                                                      4.9    R       72                                            IFO 1676                                                                      Pseudomonas diminuta IFO 12697                                                                 6.3    R       33                                            Rhodotorula glutinis IFO 0395                                                                  6.0    R       34                                            Saccharomyces cerevisiae                                                                       6.6    R       31                                            AHU 3402                                                                      Saccharomycopsis lipolytica                                                                    5.1    R       68                                            IFO 1550                                                                      Sterigmatomyces elviae                                                                         5.6    R       47                                            DSM 70852                                                                     Trichosporon curtaneum IFO 1198                                                                4.8    R       67                                            Trichosporon capitatum IFO 0743                                                                5.5    R       35                                            Agrobacterium radiobacter                                                                      5.5    S       40                                            IFO 12664                                                                     Azotobacter chroococcum                                                                        6.4    S       21                                            IFO 12994                                                                     Bacillus brevis IFO 3331                                                                       6.2    S       27                                            Bacillus cereus AHU 1707                                                                       7.5    S       41                                            Bacillus cereus AHU 1355                                                                       6.0    S       49                                            Bacillus sphaericus IFO 3525                                                                   6.0    S       42                                            Bacillus sphaericus IFO 3341                                                                   6.3    S       29                                            Bacillus subtilis IFO 3007                                                                     5.9    S       54                                            Bacillus subtilis IFO 3037                                                                     7.0    S       25                                            Bretfanomyces abstines                                                                         6.8    S       29                                            DSM 70726                                                                     Candida cariosilignicola                                                                       5.2    S       70                                            DSM 2148                                                                      Candida kefyr (Beijerinck)                                                                     5.9    S       47                                            DSM 70073                                                                     Candida krusei (Castellani)                                                                    6.1    S       47                                            DSM 70075                                                                     Candida succiphila DSM 2149                                                                    6.5    S       50                                            Candida utilis IFO 0639                                                                        4.3    S       91                                            Candida utilis IFO 0626                                                                        4.9    S       76                                            Citrobacter freundii AHU 1534                                                                  5.1    S       69                                            Corynebacterium glutamicum                                                                     6.9    S       21                                            ATCC 13032                                                                    Corynebacterium michiganense                                                                   5.0    S       73                                            IFO 13762                                                                     Dekkera bruxellensis IFO 1590                                                                  5.9    S       32                                            Endomyces decipien IFO 0102                                                                    6.8    S       21                                            Erwinia carotovora subsp.                                                                      6.5    S       21                                            carotovora IFO 3830                                                           Geotrichum fragrans JCM 1749                                                                   6.0    S       31                                            Hansenula anomala DSM 70130                                                                    2.4    S       26                                            Hansenula minuta DSM 70274                                                                     4.6    S       58                                            Hansenula subpelliculosa                                                                       4.4    S       71                                            IFO 0808                                                                      Hansenula wickerhamii DSM 70280                                                                5.1    S       47                                            Hansenula wingei DSM 10281                                                                     5.8    S       59                                            Issatchenkia scutulata var.                                                                    6.8    S       4 6                                           scutulata IFO 10070                                                           Klebsiella pneumonias IFO 12059                                                                7.0    S       24                                            Kluyveromyces drosophilarum                                                                    5.7    S       36                                            IFO 1012                                                                      Kluyveromyces lactis IFO 1267                                                                  4.9    S       76                                            Kluyveromyces lactis IFO 1903                                                                  5.1    S       57                                            Micrococcus luteus IFO 3333                                                                    7.0    S       21                                            Micrococcus roseus IFO 3764                                                                    6.5    S       22                                            Mycobacterium smegmatis                                                                        3.5    S       30                                            IFO 3135                                                                      Pachysolen tannophilus IFO 1007                                                                6.4    S       25                                            Paracoccus denitrificans                                                                       6.4    S       29                                            IFO 12442                                                                     Pichia cellobiosa DSM 2147                                                                     6.3    S       56                                            Pichia farinosa IFO 1163                                                                       6.2    S       23                                            Pichia heedii IFO 10020                                                                        6.5    S       40                                            Pichia heedii IFO 10019                                                                        6.1    S       45                                            Pichia lindnerii DSM 70718                                                                     7.1    S       40                                            Pichia opuntiae var.                                                                           4.5    S       95                                            thermotolerans IFO 10026                                                      Pichia opuntiae var.                                                                           4.4    S       97                                            thermotolerans IFO 10025                                                      Pichia pastoris DSM 70382                                                                      6.0    S       59                                            Pichia querquum DSM 70386                                                                      5.0    S       25                                            Pichia sargentensis DSM 70388                                                                  3.9    S       28                                            Pichia trehalophia DSM 70391                                                                   6.7    S       48                                            Protaminobacter ruber IAM 1081                                                                 6.2    S       46                                            Pseudomonas acidovorans                                                                        7.0    S       23                                            IFO 13582                                                                     Pseudomonas diminuta IFO 12697                                                                 4.2    S       51                                            Pseudomonas fluorescens                                                                        5.5    S       52                                            IFO 12055                                                                     Pseudomonas fluorescens                                                                        6.2    S       40                                            IFO 3081                                                                      Pseudomonas putida IFO 3738                                                                    5.0    S       75                                            Saccharomyces cerevisiae                                                                       6.6    S       24                                            IAM 0216                                                                      Saccharomycopsis fibuligera                                                                    5.3    S       22                                            IFO 0103                                                                      Selenotila peltata DSM 70579                                                                   5.6    S       45                                            Serratia marcescens IAM 1105                                                                   6.9    S       23                                            Stephanoascus ciferrii IFO 1854                                                                4.2    S       78                                            Xanthomonas maltophilia                                                                        5.1    S       41                                            IFO 12690                                                                     Xanthomonasryzae IAM 1657                                                                      6.2    S       34                                            __________________________________________________________________________         Example 6

100 ml of a YM medium comprising 0.3% of yeast extract, 0.3% of maltextract, 0.5% of peptone and of glucose and having a pH of 6.0 in thecase of yeast strains or 100 ml of a YMP medium comprising 2% ofglucose, 0.5% of yeast extract, 0.3% of peptone, 0.3% of meat extract,0.2% of (NH₄)₂ HPO₄ and 0.1% of KH₂ PO₄ and having a in the case ofbacterial strains was put in a 500-ml Sakaguchi flask. Aftersterilization followed by the inoculation with a microorganism shown inTable 2, reciprocal shaking culture was conducted at 30° C. for 48 h.Cells were separated by centrifugation and washed once withphysiological saline to give viable cells.

50 ml of distilled water was put in a 500-ml Sakaguchi flask and theviable cells obtained above was suspended therein. 5 g of glucose wasadded to the suspension. After the reciprocal shaking at 30° C. for 10min, 0.5 g of 4-hydroxy-2-butanone was added thereto and the reactionwas conducted under the reciprocal shaking at 30° C. for 20 h.

After the completion of the reaction, the cells were removed bycentrifugation and the supernatant liquid thus obtained was saturatedwith sodium chloride. After extraction with 50 ml of ethyl acetate, theethyl acetate layer was analyzed according to gas chromatography todetermine the reaction yield.

Then the ethyl acetate layer was dehydrated with anhydrous Glauber'ssalt and the solvent was removed to give a syrup. The syrup wasacetylated with acetyl chloride and dissolved in a solvent. The absoluteconfiguration and optical purity of the product were determinedaccording to high performance liquid chromatography. The results areshown in Table 2.

Example 7

Candida utilis IAM 4277 was put in a 10-l jar fermenter containing 5 lof a YM medium and cultured under stirring at 250 r.p.m. at 30° C. for48 h. The flow rate was 0.5 v.v.m.

After the completion of the culture, the cells were collected byfiltration, washed with 5 l of water and suspended in 500 ml of water. 5g of 4-hydroxy-2-butanone and 50 g of glucose were added to thesuspension and the mixture was stirred at 30° C. for 24 h to conduct thereaction.

After the completion of the reaction, the cells were removed bycentrifugation. The obtained supernatant liquid was saturated withsodium chloride and extracted with 250 ml of ethyl acetate twice. Theethyl acetate layer was analyzed according to gas chromatography toreveal that the reaction yield was 85%.

Then the ethyl acetate layer was dehydrated with anhydrous Glauber'ssalt. After removing the solvent under reduced pressure, 4.0 g of asyrup was obtained. The syrup was distilled to give colorlesstransparent (R)-1,3-butanediol.

The absolute configuration and optical purity of the obtained1,3-butanediol determined by HPLC were that of the (R)-enantiomer and94% e.e., respectively.

Example 8

Kluyveromyces lactis IFO 1267 was cultured and the reaction andextraction were conducted in the same manner as that of Example 7 togive 4.5 g of a syrup. The reaction yield was 95%, and the absoluteconfiguration and optical purity of the obtained 1,3-butanediol werethat of the (R)-enantiomer and 92% e.e., respectively.

Example 9

Candida parapsilosis IFO 1396 was cultured and the reaction andextraction were conducted in the same manner as that of Example 7 togive 3.5 g of a syrup. The reaction yield was 64% and the absoluteconfiguration and optical purity of the obtained 1,3-butanediol werethat of the (S)-enantiomer and 98% e.e., respectively.

Example 10

Geotrichum candidam IFO 4601 was cultured and the reaction andextraction were conducted in the same manner as that of Example 7 togive 3.2 g of a syrup. The reaction yield was 78% and the absoluteconfiguration and optical purity of the obtained 1,3-butanediol werethat of the (S)-enantiomer and 88% e.e., respectively.

                                      TABLE 2                                     __________________________________________________________________________                        Reaction     Optical                                                          yield                                                                              Absolute                                                                              purity                                       Microorganism       (%)  configuration                                                                         (% e.e.)                                     __________________________________________________________________________    Ambrosiozyma cicatricosa IFO 1846                                                                 46   R       48                                           Bacillus sereus AHU 1355                                                                          25   R       55                                           Bacillus subtilis IFO 3007                                                                        23   R       64                                           Candida cariosilignicola DSM 2148                                                                 34   R       85                                           Candida arborea IAM 4147                                                                          37   R       99                                           Candida kefyr (Beijerinck) DSM 70073                                                              43   R       54                                           Candida krusei (Castellani) DSM 70075                                                             41   R       59                                           Candida succiphila DSM 2149                                                                       57   R       64                                           Candida utilis IFO 0639                                                                           86   R       95                                           Candida utilis IFO 0626                                                                           76   R       93                                           Candida utilis IAM 4277                                                                           82   R       95                                           Citrobacter freundii AHU 1534                                                                     54   R       69                                           Corynebacterium michiganense IFO 13762                                                            46   R       73                                           Hansenula polymorphs ATCC 26012                                                                   96   R       85                                           Hansenula minuta DSM 70274                                                                        34   R       45                                           Hansenula subpelliculosa IFO 0808                                                                 56   R       76                                           Hansenula fabianii IFO 1254                                                                       26   R       67                                           Hansenula wickerhamii DSM 70280                                                                   43   R       45                                           Hansenula&ingei DSM 10281                                                                         47   R       64                                           Issatchenkia scutulata var. scutulata                                                             45   R       99                                           IFO 10070                                                                     Issatchenkia scutulata IFO 10069                                                                  50   R       93                                           Kluyveromyces drosophilarum IFO 1012                                                              43   R       42                                           Kluyveromycesactis IFO 1267                                                                       98   R       93                                           Kluyveromyces lactis IFO 1903                                                                     88   R       92                                           Pichia cellohios DSM 2147                                                                         76   R       79                                           Pichia heedii IFO 10019                                                                           35   R       86                                           Pichia heedii IFO 10020                                                                           24   R       81                                           Pichia lindnerii DSM 70718                                                                        20   R       78                                           Pichia opuntiae var. thermotolerans                                                               54   R       94                                           IFO 10025                                                                     Pichia pastoris DSM 70382                                                                         58   R       87                                           Pichia trehalophia DSM 70391                                                                      56   R       83                                           Protaminobacter ruber IAM 1081                                                                    43   R       62                                           Pseudomonas diminuta IFO 12697                                                                    42   R       65                                           Pseudomonas fluorescene IFO 3081                                                                  53   R       76                                           Pseudomonas putida IFO 3738                                                                       53   R       85                                           Stephanoascus ciferrii IFO 1854                                                                   40   R       60                                           Rhodotorula rubra IFO 0383                                                                        16   R       53                                           Selenotila peltata DSM 70579                                                                      25   R       62                                           Schizosaccharomyces pombe IFO 0363                                                                25   R       35                                           Xanthomonas maltophilia IFO 12690                                                                 34   R       59                                           Brevibacterium iodinum IFO 3558                                                                   56   S       85                                           Candida rugosa IFO 1364                                                                           53   S       63                                           Candida parapsilosis IFO 0640                                                                     55   S       90                                           Candida parapsilosis IFO 0708                                                                     51   S       94                                           Candida parapsilosis IFO 1396                                                                     60   S       98                                           Geotrichum candidam IFO 4601                                                                      78   S       88                                           Geotrichurt candidam IFO 5767                                                                     45   S       90                                           Geotrichum candidam IFO 5368                                                                      65   S       93                                           Geotrichum retangulatum JCM 1750                                                                  45   S       81                                           Geotrichum klebahnii JCM 2171                                                                     54   S       75                                           Geotrichum fermentans JCM 2467                                                                    48   S       77                                           Geotrichum capitatum JCM 3908                                                                     44   S       81                                           Geotrichum eriense JCM 3912                                                                       51   S       68                                           Klebsiella pneumonias IFO 1209                                                                    32   S       30                                           Lodderomyces elongisporus IFO 1676                                                                62   S       70                                           Saccharomycopsis lipolytica IFO 1550                                                              61   S       65                                           Trichosporon curtaneum IFO 1198                                                                   64   S       80                                           Trichosporon capitatum IFO 0743                                                                   25   37                                                   __________________________________________________________________________

It is claimed:
 1. A process for producing optically active1,3-butanediol which comprises (1) treating a mixture of 1,3-butanediolenantiomers with a microorganism capable of asymmetrically assimilatingsaid mixture, leaving either the (R)- or the (S)-enantiomer intact, soas to produce optically active 1,3-butanediol, said microorganism to beselected from the group consisting of:Brevibacterium iodinum Candidaparapsilosis Enterobacter cloacae Geotrichum candidum Geotrichumrectangulatum Geotrichum klebahnii Geotrichum fermentans Geotrichumcapitatum Geotrichum eriense Lodderomyces elongisporus Pseudomonasdiminuta Rhodotorula glutinis Saccharomycopsis lipolytica Trichosporoncutaneum Agrobacterium radiobacter Azotobacter chroococcum Bacilluscereus Bacillus subtilis Brettanomyces abstines Candida cariosilignicolaCandida kefyr (Beijerinck) Candida krusei (Castellani) Candidasucciphila Candida utilis Citrobacter freundii Corynebacteriumglutamicum Corynebacterium michiganense Dekkera bruxellensis Endomycesdecipiens Erwinia carotovora subsp. cartovora Geotrichum fragransHansenula anomala Hansenula minuta Hansenula subpelliculosa Hansenulawickerhamii Hansenula wingei Issatchenkia scutulata var. scutulataKlebsiella pneumoniae Kluyveromyces lactis Micrococcus luteusMycobacterium smegmatis Pachysolen tannophilus Paracoccus denitrificansPichia cellobiosa Pichia lindnerii Pichia opuntiae var. thermotoleransPichia pastoris Pichia querquum Pichia sargentensis Pichia trehalophilaPseudomonas diminuta Pseudomonas putida Selenotila peltata Serratiamarcescens Stephanoascus ciferrii and Xanthomonas maltophiliaand (2)collecting the optically active 1,3-butanediol remaining intact.
 2. Aprocess according to claim 1, wherein the microorganism is capable ofleaving (R)-1,3 -butanediol intact, said organism being selected fromthe group consisting of:Brevibacterium iodinum Candida parapsilosisEnterobacter cloacae Geotrichum candidum Geotrichum rectangulatumGeotrichum klebahnii Geotrichum fermentans Geotrichum capitatumGeotrichum eriense Klebsiella pneumoniae Lodderomyces elongisporusPseudomonas diminuta Rhodotorula glutinis Saccharomycopsis lipolyticaand Trichosporon cutaneum.
 3. A process according to claim 2, whereinsaid microorganism has been immobilized.
 4. A process according to claim1, wherein the microorganism is capable of leaving (S)-1,3-butanediolintact, said organism being selected form the group consistingof:Agrobacterium radiobacter Azotobacter chroococcum Bacillus cereusBacillus subtilis Brettanomyces abstines Candida cariosilignicolaCandida kefyr (Beijerinck) Candida krusei (Castellani) Candidasucciphila Candida utilis Citrobacter freundii Corynebacteriumglutamicum Corynebacterium michiganense Dekkera bruxellensis Endomycesdecipiens Erwinia carotovora subsp. cartovora Geotrichum fragransHansenula anomala Hansenula minuta Hansenula subpelliculosa Hansenulawickerhamii Hansenula wingei Issatchenkia scutulata var. scutulataKlebsiella pneumoniae Kluyveromyces lactis Micrococcus luteusMycobacterium smegmatis Pachysolen tannophilus Paracoccus denitrificansPichia cellobiosa Pichia lindnerii Pichia opuntiae var. thermotoleransPichia pastoris Pichia querquum Pichia trehalophila Pseudomonas diminutaPseudomonas putida Selenotila peltata Serratia marcescens Stephanoascusciferrii and Xanthomonas maltophilia.
 5. A process according to claim 4,wherein said microorganism has been immobilized.
 6. A process accordingto claim 1, wherein said microorganism has been immobilized.
 7. Aprocess for producing optically active 1,3-butanediol which comprises(1) treating a mixture of 1,3-butanediol enantiomers with amicroorganism capable of asymmetrically assimilating said mixture,leaving either the (R)- or the (S)-enantiomer intact to produceoptically active 1,3-butanediol, said microorganism to be selected fromthe group consisting of:Brevibacterium iodinum Klebsiella pneumoniaeLodderomyces elongisporus Pseudomonas diminuta Pseudomonas putidaRhodotorula glutinis Saccharomycopsis lipolytica Trichosporon cutaneumAgrobacterium radiobacter Azotobacter chroococcum Bacillus subtilisCorynebacterium michiganense Dekkera bruxellensis Endomyces decipiensErwinia carotovora subsp. cartovora Hansenula subpelliculosaIssatchenkia scutulata var. scutulata Micrococcus luteus Mycobacteriumsmegmatis Pachysolen tannophilus Paracoccus denitrificans Stephanoascusciferrii and Xanthomonas maltophiliaand (2) collecting the opticallyactive 1,3-butanediol remaining intact.
 8. A process according to claim7, wherein said microorganism has been immobilized.
 9. A process forproducing optically active 1,3-butanediol which comprises (1) treating amixture of 1,3-butanediol enantiomers with a microorganism, capable ofasymmetrically assimilating said mixture, said microorganism to beselected from the group consisting of:

    ______________________________________                                        Brevibacterium iodinum                                                                             IFO      3558                                            Candida parapsilosis IFO      1396                                            Enterobacter cloacae ATCC     7256                                            Geotrichum candidum  IFO      5368                                            Geotrichum rectangulatum                                                                           JCM      1750                                            Geotrichum klebahnii JCM      2171                                            Geotrichum fermentans                                                                              JCM      2467                                            Geotrichum capitatum JCM      3908                                            Geotrichum eriense   JCM      3912                                            Klebsiella pneumoniae                                                                              IFO      12009                                           Lodderomyces elongisporus                                                                          IFO      1676                                            Pseudomonas diminuta IFO      12697                                           Rhodotorula glutinis IFO      0395                                            Saccharomycopsis lipolytica                                                                        IFO      1550                                            Trichosporon cutaneum                                                                              IFO      1198                                            Agrobacterium radiobacter                                                                          IFO      12664                                           Azotobacter chroococcum                                                                            IFO      12994                                           Bacillus cereus      AHU      1707                                            Bacillus subtilis    IFO      3007                                            Brettanomyces abstines                                                                             DSM      70726                                           Candida cariosilignicola                                                                           DSM      2148                                            Candida kefyr (Beijerinck)                                                                         DSM      70073                                           Candida krusei (Castellani)                                                                        DSM      70075                                           Candida succiphila   DSM      2149                                            Candida utilis       IFO      0639                                            Citrobacter freundii AHU      1534                                            Corynebacterium glutamicum                                                                         ATCC     13032                                           Corynebacterium michiganense                                                                       IFO      13762                                           Dekkera bruxellensis IFO      1590                                            Endomyces decipiens  IFO      0102                                            Erwinia carotovora subsp.                                                                          IFO      3830                                            cartovora                                                                     Geotrichum fragrans  JCM      1749                                            Hansenula anomala    DSM      70130                                           Hansenula minuta     DSM      70274                                           Hansenula subpelliculosa                                                                           IFO      0808                                            Hansenula wickerhamii                                                                              DSM      70280                                           Hansenula wingei     DSM      10281                                           Issatchenkia scutulata var.                                                                        IFO      10070                                           scutulata                                                                     Klebsiella pneumoniae                                                                              IFO      12059                                           Kluyveromyces lactis IFO      1267                                            Micrococcus luteus   IFO      3333                                            Mycobacterium smegmatis                                                                            IFO      3135                                            Pachysolen tannophilus                                                                             IFO      1007                                            Paracoccus denitrificans                                                                           IFO      12442                                           Pichia cellobiosa    DSM      2147                                            Pichia lindnerii     DSM      70718                                           Pichia opuntiae var. IFO      10025                                           thermotolerans                                                                Pichia pastoris      DSM      70382                                           Pichia querquum      DSM      70386                                           Pichia sargentensis  DSM      70388                                           Pichia trehalophila  DSM      70391                                           Pseudomonas putida   IFO      3738                                            Selenotila peltata   DSM      70579                                           Serratia marcescens  IAM      1105                                            Stephanoascus ciferrii                                                                             IFO      1854 and                                        Xanthomonas maltophilia                                                                            IFO      12690                                           ______________________________________                                    

and (2) collecting the optically active 1,3-butanediol remaining intact.10. A process according to claim 9, wherein the microorganism is capableof leaving (R)-1,3-butanediol intact, said organism being selected fromthe group consisting of:

    ______________________________________                                        Brevibacterium iodinum                                                                             IFO      3558                                            Candida parapsilosis IFO      1396                                            Enterobacter cloacae ATCC     7256                                            Geotrichum candidum  IFO      5368                                            Geotrichum rectangulatum                                                                           JCM      1750                                            Geotrichum klebahnii JCM      2171                                            Geotrichum fermentans                                                                              JCM      2467                                            Geotrichum capitatum JCM      3908                                            Geotrichum eriense   JCM      3912                                            Klebsiella pneumoniae                                                                              IFO      12009                                           Lodderomyces elongisporus                                                                          IFO      1676                                            Pseudomonas diminuta IFO      12697                                           Rhodotorula glutinis IFO      0395                                            Saccharomycopsis lipolytica                                                                        IFO      1550 and                                        Trichosporon curtaneum                                                                             IFO     
 1198.                                           ______________________________________                                    


11. A process according to claim 9, wherein the microorganism is capableof leaving (S)-1,3-butanediol intact, said organism being selected formthe group consisting of:

    ______________________________________                                        Agrobacterium radiobacter                                                                          IFO      12664                                           Azotobacter chroococcum                                                                            IFO      12994                                           Bacillus cereus      AHU      1355                                            Bacillus subtilis    IFO      3007                                            Brettanomyces abstines                                                                             DSM      70726                                           Candida cariosilignicola                                                                           DSM      2148                                            Candida kefyr (Beijerinck)                                                                         DSM      70073                                           Candida krusei (Castellani)                                                                        DSM      70075                                           Candida succiphila   DSM      2149                                            Candida utilis       IFO      0639                                            Citrobacter freundii AHU      1534                                            Corynebacterium glutamicum                                                                         ATCC     13032                                           Corynebacterium michiganense                                                                       IFO      13762                                           Dekkera bruxellensis IFO      1590                                            Endomyces decipiens  IFO      0102                                            Erwinia carotovora subsp.                                                                          IFO      3830                                            catovora                                                                      Geotrichum fragrans  JCM      1749                                            Hansenula anomala    DSM      70130                                           Hansenula minuta     DSM      70274                                           Hansenula subpelliculosa                                                                           IFO      0808                                            Hansenula wickerhamii                                                                              DSM      70280                                           Hansenula wingei     DSM      10281                                           Issatchenkia scutulata var.                                                                        IFO      10070                                           scutulata                                                                     Klebsiella pneumoniae                                                                              IFO      12059                                           Kluyveromyces lactis IFO      1267                                            Micrococcus luteus   IFO      3333                                            Mycobacterium smegmatis                                                                            IFO      3135                                            Pachysolen tannophilus                                                                             IFO      1007                                            Paracoccus denitrificans                                                                           IFO      12442                                           Pichia cellobiosa    DSM      2147                                            Pichia lindnerii     DSM      70718                                           Pichia opuntiae var. IFO      10025                                           thermotolerans                                                                Pichia pastoris      DSM      70382                                           Pichia querquum      DSM      70386                                           Pichia sargentensis  DSM      70388                                           Pichia trehalodhila  DSM      70391                                           Pseudomonas diminuta IFO      12697                                           Pseudomonas putida   IFO      3738                                            Selenotila peltata   DSM      70579                                           Serratia marcescens  IAM      1105                                            Stephanoascus ciferrii                                                                             IFO      1854 and                                        Xanthomonas maltophilia                                                                            IFO     
 12690.                                          ______________________________________                                    


12. A process according to claim 9, wherein said microorganism has beenimmobilized.
 13. A process according to claim 9, wherein saidmicroorganism is collected, washed and resuspended in water or a buffer.